A system of photographing an area around a vehicle through a plurality of cameras installed in the vehicle and displaying a video in the vehicle so that a driver can check the area around the vehicle while driving the vehicle has been already proposed, and such a known system also includes a technique of displaying a video in which the area around the vehicle is viewed from a virtual viewpoint by appropriately transforming and synthesizing the videos photographed by a plurality of cameras installed in the vehicle.
In such a video display system, a technique of arranging a projection plane on a virtual space, mapping a camera video, creating a video viewed from a virtual viewpoint in the space, and displaying the video is known. In this case, it is common that, when a difference occurs in a shape between a subject photographed by the camera and the virtual projection plane, a video that is transformed and synthesized is viewed to be distorted due to the difference. For example, when the subject photographed by the camera is a three-dimensional (3D) object such as a person or a guardrail, and the virtual projection plane is a plane that is equal in height to the ground surface and parallel to the ground surface, the 3D object is distorted to be an elongated video in a video that is transformed and synthesized, and thus the user is unable to understand a situation. In order to solve such a problem, various techniques regarding a method of generating a video that is transformed and synthesized have been disclosed in the past.
For example, Patent Document 1 discloses a technique of changing a shape of a virtual projection plane and a position and an angle of a virtual viewpoint according to a state of a vehicle.